Internal combustion engine



J. J. MQCARTHY INTERNAL COMBUSTION ENGINE 7 Filed June 4, 1932 Jan; 12, 1937'.

4 Sheets-Sheet l I14 ve flier J. J. M CARTHY I INTERNAL COMBUSTICDN ENGINE FiledJune 4, 1952 4 Sheets-Shet 2 jiveizioz Jam. 12, 1937 J, J. MCCARTHY 2,067,496

INTERNAL COMBUSTION ENGINE Filed June 4; 1932 4 Sheets-Sheet 5 V i ,l/ i5 15 "Z2 1') l 144': 17 "2% 1 Q v 'Iwvewi'or Jan. 12, 1937. J. J. M CARTHY INTERNAL COMBUSTION ENGINE Filed June 4, 1932 4 Sheets-Sheet 4 Patented Jan. 12, 1937 S'iATE-S PATENT oFFic 10 Claims.

My present invention relates to internal combustion engines of the type wherein each cylinder has two concentric pistons, the outer piston being in the form of a sleeve in which the inner piston 5 reciprocates, and both being arranged to reciprocate in time relation and in opposite directions, my present invention being an improvement of my prior United States Letters Patents Nos. 1,823,500, dated September 15, 1931, and 1,903,511,

dated April 11, 1933.

Important objects of my present invention are to improve and perfect engines of the doubleopposed piston type, to render them free of vibration, and provide substantially perfect balanced construction andoperati'on; to have means which will quickly, completely, and automatically clean out and scavenge the consumed gases from the cylinders through the action of the reciprocating,

pistons; to insure the correct lubrication of the double-opposed pistons by positively drawing oil vapor from the crank case to the top of the cylinder, and to improve and perfect engines of the double-opposed cylinder type.

Preferably my invention is embodied in an and operating on the two-stroke cycle principle, which latter is peculiarly advantageous in a double-opposed piston type, wherein an engineof given power will be compact, have fewer parts, and requires only about one-half the number of cylinders to produce the same power as double the cylinders in a four-stroke cycle engine.

My novel method of scavenging the cylinders ispositive and most important; and for relatively high-powered units a. rotary blower would be utilized for this purpose, although a single air-pump piston would be suitable for small lower-powered units.

an important feature is the arrangement of a circular manifold permitting the intake air to enter in a tangential manner, thus inducing swirling currents of air in the working cylinders between the pistons, which air furnishes the highly desired turbulence for Diesel operation.

In the drawings, illustrating a preferred embodiment of the invention, a two-cylinder engine operating on the Diesel or compression ignition cycle is shown.

Fig. 1 is a longitudinal sectional view. The left-hand'cylinder shall be designated as cylinder #l hereafter, likewise cylinder #2 is the right-hand cylinder.

Fig. 2 is a longitudinal elevation.

Fig. 3 is a transverse section showing the pisengine of the Diesel or compression ignition type,

ton #l part way down and the sleeve #2 partlyup on their respective power strokes. a

Fig. 4 shows a modification of Fig. 3. Fig. 4 contains the enlarged scavenge pump piston #28 with a transfer valve #26 as predominant 5 feature.

Fig. 5 is likewise another modification of Fig. .3. Fig. 5 embodies an enlarged single-acting pump piston #39 attached to sleeve #2.

Fig. 6 is part of transverse view with precom- =bu'stion chamber #4! external to working cylinder. Figs. 7 and 8 are horizontal sections through intake and exhaust ports respectively.

.Beferring now to Fig. 1 for a specific description of the construction features embodied in my invention, l is the working piston with piston rings II, and linked to the crankshaft 'l' by a connecting rod 6. The piston pin I! has suitable plugs l3 made of soft alloy to prevent piston pin from scoring sleeve 2. Said piston I reciprocates within sleeve 2. At the bottom of said sleeve 2 are two bosses 4 diametrically opposite and the axes-of said bosses l are parallel to center line of crankshaft I.

Two short connecting rods 5 of equal length connect said working sleeve to crankshaft. The crankthrow for rod 6 is nearly opposite that for the short rods 5. The crankshaft I is mounted on main bearings I0, the latter are supported by crankcases 8 and 9. Onto crankcase 8 is mounted a cylinder block I8. Said working sleeve reciprocates in cylinder block l8. In the cylinder block and said sleeve are intake and exhaust ports 14 and I6, respectively. Similarly l5 and II are intake and exhaust manifolds respectively. l The water jacket is l9. Attached to the upper end of the sleeve is a head 3. In cylinder l the piston is at the bottom dead center and the sleeve is near or at top dead center revealing the working cylinder 20. In the combustion chamber (in cylinder No. 2) is an end view of injection nozzle 24. The top cover 2! serves onlyv as a case and communicates to the crankcase by breather passage 25. 4

In Fig. 2 the intake and exhaust pipes 22 and 23 respectively are the only parts not shown in Fig. 1. The intake pipe 22 is connected to a rotary blower which is not shown on these drawings. The injection nozzles 24 are here indicated more clearly than in Fig. 1. 1

Fig. 3 shows the relative positions of the crankthrows on the crankshaft I. In this case the included angle between said crankthrows is 170. In other words, if the rotation is clock- 65 2 v x v wise, the crankthrow for the piston leads that for the sleeve by 10. All parts in this figure are I surround the cage supporting inlet check 'valves 32. The latter are mounted in pump cylinder head 33. A piston ring 33 is used on pump pisv of in working cylinder .23.

ton 23. In a valve guide 23 secured in pump piston 23-slides a transfer valve 23. Said transfer valve seats upon valve seat 21, the latter being secured to pump piston 23. There are not vintake ports in this arrangement but transfer of compressed charge takes place past the check valve 23.;

In Fig. 5, 34 indicates inlet passages, 32 are inlet check valves, 3| is a pump cylinder, 33 are outlet check valves connecting into passages: 33 and thence to ports in cylinder block l3 and corresponding ports I4 in sleeve 2. The pump piston 39 also forms head on sleeve 2 and is ris idly attached thereon and reciprocates with said sleeve 2. Space 43 is connected by breather pipes to crankcase.

Fig. 6 is similar to Fig. 3 except that combustion occurs in precombustion chamber 4| instead 44 is an orifice connecting said precombustion chamber 4| with cylinder 23. This precombustion chamber 4| is spherical 'in shape and injection nozzle 24 is screwed into said chamber. 'A glow plug 43 to furnish heat from an electric current through wire 43 for starting ease in cold/ weather is illustrated.

Fig. 7 and Fig. 8 are sections through intake and exhaust ports respectively, where said ports are open, as is shown in cylinder No. l of Fig. 1..

The manifold 13 extends around the cylinder and is an integral part of cylinder block I31 in Fig. 1. Ports l4 arearranged so as to enable air to flow into cylinder 23 from all'sides. The center line of said ports i4 is so placed as to produce atangential flow into'cylinder 23. On the 3 other hand, the exhaust ports l3 in Fig. 8 are arranged to conduct the rotation of exhaust gases out with the least amount of resistance into manifold I1.-

The operation of my engine is very simple and will be readily understood by those skilled in this art, being described as follows.

' If we assume that the engine is a two-cylinder engine, constructed as described above and asillustrated in the drawings, suchoperation will be as follows: v

The motor will be rotated by a erank'or conventional starter. Referring to Fig. 1, air will be furnished under pressure from a scavenging pump or blower driven from the engine, to cylinder No. I through intake pipe 22 (Fig. 2)., manifold. l3. and ports 14, thence into cylinder 23. 'As crankshaft I rotates the piston I travels 'uppump operated from the timing mechanism of the engine. As the combustion progresses the to crankshaft 1. Connecting rod 3 exerting a revolution of the crankshaft I and the component parts are now in a position as shown in cylinder No. I of Fig. 1, ready for the above described cycle to be repeated.

During the operation of the engine there will be changes in the volume and pressure under case 2| and this compartment is connected by' passage 23 to enable oil vapor to be drawn up and lubricate the upper end of cylinder in which .the sleeve 2 and head 3 operate.

InFig. 4 the single acting pump piston is on the-downward or intake stroke. The air flows through passages 34 and past the check valve .32 into pump cylinder 3|. when the pump piston23 reaches the bottom of its stroke, a full charge of air will havebeen taken in and the automatic valves 32 will close.- On the return when the piston l nears the bot-' stroke valve 23 will be opened automatically by pressed air will flow from the pump cylinder into cylinder 23, thus filling said cylinder 23 with a fresh charge of air and also scavenging from it the residual products. Shortly after the pump cylinder 28 reaches'top dead center the transfer valve 23 closes automatically and the charge of air just introduced into cylinder 23 is ready 'for the "compression stroke when sleeve 2 moves downthe pressure built up in cylinder 3i and the comward again. The piston ring 33 on the pumppiston 23 seals said pump piston in cylinder 3i. The space in cylinder 3| beneath the enlarged part of pump piston 23 is connected to the crank case so that oil vapor may be circulated in said space and lubricate the upper part of the cylinder in which the sleeve 2 reciprocates.

Similar to- Fig. 4 is Fig. 5 which contains a single acting pump piston 33 without a transfer valve as a combined feature. Said pump piston 33 is on the intake or suction stroke. The air is induced to flow from the outside through passages 34 and past the automatic valves 32 into cylinder 3| until said pump piston 33 has approximately reached the bottom dead center position. At this time the inlet' check valves 32 close and the sleeve 2 along with the pump piston 33'returns upwards and compresses the air in cylinder 3i until the automatic outlet check valves 33 open. Y

The compressed charge of air then flows into passage 33 and when the'sleeve -2 along with pump piston 33 nears its uppermost position, the intake ports into cylinder 23 are uncovered and the charge of air flows into saidworking cylinder 23. scavenging of the residual products of combustion and a fresh charge of air is obtained in working cylinder 23. Said outlet valves 33 close when the pump piston 33 again starts downward.

l-leretofore, the combustion has been described as taking place in the working cylinder 20. In Fig. 6 the operation is the same as described for Figs. 1 and 3, except that on the compression stroke the air is forced into a precombustion chamber 4i through an orifice 44 so as to produce a high rate of turbulence or rotation in said chamber M. At or near the top dead center of piston i and likewise near bottom dead center of the sleeve 2 with head 3, fuel is injected at the properly timed interval through nozzle 14 into the whirling air in chamber 4|, which is at a high temperature, due (to compression. Combustion then takes place in said precombustion chamber 6! and the pressure and temperature of the charge rise and the charge escapes through orifice 4 into the working cylinder 28. Piston I is then forced downward and the pressure on head 3 drives the sleeve upward similar to the operation for Fig. l and Fig. 3. When the motor is very cold at starting, the glow plug 53 can be putinto action by passing an electric current through the coil of wire 42 and thus heating said coil so that when the injected fuel and air pass rapidly over this hot wire, combustion will take place more readily by raising the temperature of the charge.

In Fig. 7 the intake air flows into the circular manifold i5 and flows around it in a rotating manner. At properly timed intervals the sleeve 2 with ports to match those in cylinder block i8 uncovers said ports 14 and permits thecharge 01 air to flow into working cylinder 20 in a tangential manner. This induces an orderly rotation of the air in the working cylinder 20 which iurnishes the required turbulence for Diesel operation.

Fig. 8, section through exhaust ports, operates in the reverse manner'to that of intake of the charge shown.in Fig. 7.

I claim:

1. An internal combustion engine of the kind described having a cylinder containing a pair of concentrically mounted opposed pistons arranged to move in opposite directions with respect to each other, one of said pistons being in.

the ;form of a sleeve, and the other piston oper-.- ating within said sleeve in timed relation and in the opposite direction, said sleeve carrying an air pump at the end opposite the engine crank shaft, transfer passages leading from said pump to said cylinders, and means associated with said passages eflecting a tangential air delivery into the: working chamber between said pistons operating at properly timed intervals based upon ports in said working sleeve uncovering portsin said cylinder.

. 2. An internal combustion engine .01 the kind described operating on the two-stroke cycle and compression ignition principle, having a plurality of cylinders, each cylinder containing a pair oi! concentrically mounted opposed pistons arranged to move in timed relation and in opposite directions respectively, one of each of said pistons in the form oi a sleeve, and the companion piston operating within'said sleeve, each sleeve carrying an air pump. at the end opposite the engine crank shait, transfer passages leading from said pump to saidcylinderl, 'said passages terminating in ports tangentially arranged with respect to said cylinders to eflect a tangential air delivery into the working chambers between said pistons operating at properly timed intervals based upon ports insaid working sleeve uncovering ports in said cylinder.

3. An internal combustion engine having opposed reciprocating pistons in the cylinder, one of said pistons having a sleeve and the other piston operatingwithin said sleeve in timed relation and in the opposite direction, a passage from the crank case to the upper part of the engine, a manifold adjacent said cylinder, tangentially arranged ports associated with said manifold, ports in said sleeve piston adapted to cooperate with said maniioldports to scavenge said cylinder on the exhaust stroke, said sleeve piston operating on the compression stroke to feed oil vapor from the crankcase to the upper port of the engine.

4. An internalcombustion engine operating on the two-cycle and compression ignition principles, having a plurality of sets of opposed reciprocating pistons in each cylinder, one of each 01' said pistons having an outer sleeve in contact with the cylinder walls, and with the inner part of said sleeve constituting the walls tor the opposed piston operating within said sleeve, means supplying air under pressure around said cylinder, ports in the cylinder cooperating with a plurality of sets of ports in each sleeve of the outer piston of a. pair, providing tangential in-.

iection o1 scavenging air at proper intervals between said pistons. in combination with means automatically actuated by the reciprocation of one of said pistons to insure the oiling oi the upper part of said cylinder and sleeve.

5. An internal] combustion engine operating on the two-cycle'and compression ignition principles, having a cylinder with two pistons operating in opposite directions, one piston comprising a sleeve in which the oppositely moving piston operates, said sleeve having a set of intake ports nearj the upper end, and a set of exhaust ports near the lower end, a maniIold adJacent said-cylinder, cylinder intake ports associated with said manifold and arranged to cooperate with said sleeve intake ports to provide a tangential air intake for scavenging the burnt gases on the exhaust stroke.

6. An intemai; combustion engine operating on the two-cycle and compression ignition principles, havinga plurality of sets of opposed reouter piston of a pair, providing tangential injection of scavenging air at proper intervals between said pistons based ,upon ports in the working'sleeve uncovering ports in the cylinder.

7. An internalcombustion engine of the characterdescribed operating on the two-cycle and compression ignition principles, having a cylinder with two pistons operating in opposite dircctions and forming a working chamber, one 0! said pistons comprising a sleeve, intake ports to said -working chamber. and conducting means toteedair tosa id ports, said portsbeing arranged to provide 'a tangential air intake into said working 8. An internal combustion engine or the character described ting on the two-cycle and compression igni uni-principles, having a cylinder with two operat ng in opposite di-- rections and forming a working chamber, cylinder intake ports. one piston comprising a sleeve.'

said sleeve having ports adapted to register with said cylinder ports, said cylinder ports being tangentially arranged with respect to said cylinder to direct air in a tangential flow into said exhaust stroke. said intake ports providing a tangential air flow into said working chamber to provide turbulence on the compression stroke. l0. An internal combustion engine of the character described having opposed reciprocat ing pistons in each cylinder forming a working chamber, intake ports to said working chamber,

conducting means toieed air to said ports, said means and said ports cooperating to provide a tangential air intake into said working chamber and exhaust ports tangentially arranged'with respect to said cylinder to cooperate with said tangentialintake toprovide a tangential scavenging or burnt gases from said working chamber.

JOHN 

